N-Aryl amines and amides are important substructures in natural products and industrial chemicals, such as pharmaceuticals, dyes, and agricultural products. Palladium-catalyzed methods for the N-arylation of amines and amides are now widely-exploited for the synthesis of arylamine and N-arylamide moieties in pharmaceuticals, materials with important electronic properties, and ligands for early metal catalysts. Likewise, the palladium-catalyzed coupling to form carbon-carbon bonds between an aryl or vinyl halide and a carbon nucleophile is widely used. See, e.g., Stille, J. K. Angew. Chem., Int. Ed. Engl., 25:508-524 (1986); Miyaura, N. et al., Chem. Rev., 95:2457-2483 (1995); Negishi, E. Acc. Chem. Res., 15:340-348 (1982).
However, the ever-increasing cost of palladium detracts from the allure of these powerful methods. Consequently, a need exists for a general and efficient catalytic method for synthesizing N-aryl amines and amides, from aryl halides and the corresponding amines and amides, based on a catalyst that does not comprise a rare, costly transition metal, such as palladium. Likewise, a need also exists for a general and efficient catalytic method for forming carbon-carbon bonds between an aryl or vinyl halide and a carbon nucleophile, based on a catalyst that does not comprise a rare, costly transition metal, such as palladium.
In 1998, bulk palladium sold on the international metal market for roughly five-thousand-times the cost of bulk copper. Therefore, based on catalyst cost, the aforementioned transformations would be orders of magnitude more appealing if they could be achieved with catalysts comprising copper in place of palladium.